26 • 35-3001A-13-XX CO
2
/CO Sample-Draw Detector
6. Disconnect the sample tubing from the inlet line.
7. Unscrew the regulator from the 100% nitrogen calibration cylinder.
Setting the Response Reading
1. Screw the regulator into the carbon dioxide calibration cylinder.
2. Connect the sample tubing from the demand flow regulator to the sample-draw detector’s inlet line.
3. Allow the sample-draw detector to draw sample for one minute.
4. When the reading on the voltmeter stabilizes, verify that the reading matches the response reading (±2 mV)
you determined earlier.
5. If necessary, use the span potentiometer on the amplifier to adjust the reading to match the correct response
reading.
6. Disconnect the sample tubing from the inlet line.
7. Unscrew the regulator from the carbon dioxide calibration cylinder.
Returning to Normal Operation
1. Wait approximately one minute to allow the carbon dioxide reading to stabilize.
2. Remove the voltmeter leads from the amplifier test points.
3. Close the housing door.
4. Follow the instructions in the controller’s operator’s manual to exit the calibration mode.
5. Store the components of the calibration kit in a safe and convenient place.
Calibration, CO Sensor
This section describes how to calibrate the CO sensor in the sample-draw detector. It includes procedures to
prepare for calibration, set the zero reading, set the response reading, and return to normal operation.
NOTE:
Calibrating the sample draw detector may cause alarms. Be sure to put the controller into its calibration
program or disable external alarms before continuing.
NOTE:
This procedure describes calibration using a demand flow regulator.
Preparing for Calibration
NOTE:
If you can verify a fresh air environment, it is not necessary to use a zero air calibrating sample to set
the zero reading at the controller.
1. Follow the instructions in the controller’s operator’s manual for entering calibration mode.
2. Screw the regulator into the zero air calibration cylinder.
3. Open the housing door.
4. Set a voltmeter to measure in the millivolt (mV) range.
5. Connect the voltmeter to the test points on the CO amplifier.
Plug the positive lead into the red (+) amplifier test point; plug the negative lead into the black (-) amplifier
test point.
